This is exactly what happened to me. Called 3 times within an hour and then a 3 sec message with electrical hum. I did reverse look-up and its to a Jodi near Salt Lake. I do not have a Utah number either so I was so confused. Must be a scam or solicitor.
Got 2 calls, one at 7:30p next at 8:45p. Let it go to voicemail twice and no message were left. Also Utah/SLC area code. Sounds like a dialer that is either broken so it doesn't leave a message correctly, or one of those machines that checks to see when you are "home" so other telemarketers can call you later when you are likely to answer... maybe?